Apparatus for pumping boiling liquid



Oct. 15, 1963 sc u R 3,106,827

APPARATUS FOR PUMPING BOILING LIQUID I Filed Nov. 24, 1961 F/Gf.

I n venlor fi/b/me Maar/ce 626/0075 e/yer y OW, 77/ 'M Attorney United States Patent APPARATUS FOR PUMPING BOILING LIQUID Etienne M. Schiumberger, London, England, assignor to Conch International Methane Limited, Nassau,

Bahamas, :1 Bahamian company Filed Nov. 24, 1961, Ser. No. 154,407 Claims priority, application Great Britain Feb. 28, 1951 4 Claims. (Cl. 6251) In the transport of liquefied hydrocarbon gases such as methane or propane by tanker, it is economic to use part of the liquefied gas cargo as fuel for the tankers boilers or engines. This invention relates to an economical apparatus whereby the pumping equipment used for discharging the liquefied gas cargo from the tankers storage tanks can also be used for feeding fuel gas to the boilers or engines.

Accordingly, the invention provides apparatus for pumpa boiling liquid from a container and also for pumping gas from said container when required, which comprises:

(l) A riser extending from a point near the bottom of the container,

(2) A branch on said riser communicating with the vapour space at the top of the container,

(3) Valve means in said riser and in said branch to control flow of fluids from either the bottom of the riser or the said vapour space,

(4) A separator, to the inlet of which said riser is connected,

(5 A vapour outlet from said separator connected to a compressor,

(6) A liquid outlet from said separator connected to a pump, and

(7) Valve means for controlling flow of fluid from said liquid outlet.

In a preferred arrangement, there is also a heat exchanger downstream of the pump on the liquid outlet so that vapour from the compressor may be passed in heat exchange with the cold liquid and a further separator in the vapour line downstream of the heat exchanger. From this further separator, a liquid line fitted with valve means runs back to the container, and a vapour line runs to the boilers or engines or other desired destination.

The apparatus of this invention and a method of using the same will now be described with reference to the accompanying drawings, in which:

FIGURE I shows a simple form of the invention, and

FIGURE II a more elaborate form.

Referring to FIGURE I, a riser 1 communicates from near the bottom of the container 2. to the cyclone separator 3. The riser 1 is fitted with a control valve 4 and downstream of this control valve joins a branch line 5 fitted with control valve 6. The branch line 5 communicates with the vapour space in container 2. A vapour discharge line 7 connects the top of the cyclone with a compressor 8, and a line 9 communicates the discharge from the compressor to the tankers boilers or engines and, when required, to any other destination. The liquid discharge line 10 from the bottom of the cyclone is fitted with control valve 11 and communicates with pump 12 which pumps the liquid to its destination through line 13.

During the voyage, valves 4 and 11 are closed, and valve -6 is open, and the compressor 8 pumps vapour from the vapour space of the container 2 through conduit 5 and the upper part of riser 1 and through separator 3 and line 7 into line 9 which feeds it to the tankers boilers or engines. When the tanker reaches its destination, valve 6 is closed and valves 4 and 11 are opened and now compressor 8 will cause liquid from the foot of riser 1 to flow up into separator 3 in which the vapour is separated from the liquid, and the liquid is pumped via line 10, pump 12 and line 13 to its destination on land. The separated vapour from separator 3 will pass via line 7, compressor 8 and line 9 to auxiliary engines or to a reliquefaction plant or to the land installation or back to the container or to waste.

Referring to FIGURE II, numerals 1, 2, 3, 4, 5, 6, 7, 8, 9, .10, 11, 12 and 13' have the same significance as in FIGURE I. However, in FIGURE II the discharge line 9 from the compressor 8 passes through heat exchanger 14 and then through a further separator 15, from which vapour is taken via line 16 and liquid is returned to the container 2 via line 17 and control valve 18.

In this case, when it is desired to pump vapour to the tankers engines or boilers during the voyage, valves 4, 18 and 1-1 are closed and valve 6 is open, and then compressor 8 pumps vapour from the vapour space of container 2 via line 5, the upper part of riser 1, separator 3 and lines 7, 9 and '16 to the engines or boilers. When it is desired to pump liquid from the container, valves 4, 11 and 18 are opened, and valve 6 is closed. The compressor then causes liquid to rise up riser 1 from the bottom of container 2 into separator 3, from which the liquid is pumped away by pump 12 and lines 10 and 13. The vapour separated in the separator 3 passes via line 7, compressor 8 and line 9 through heat exchanger 14 in which it is cooled against the cold liquid being pumped to storage. Some of the vapour is condensed and the condensate is separated out in separator 15 and returned to the container via line '17. The remainder of the vapour passes out through line 16.

We claim:

1. Apparatus for selectively pumping a boiling liquid from a container in which it is stored at substantially atmospheric pressure and also for pumping gas from said container when required, which comprises a riser extending from a point near the bottom of the container, a branch -on said riser communicating with the vapour space at the top of the container, valve means in said riser and in said branch to selectively control flow of fluids from either the bottom of the riser or the said vapour space, a separator, having an inlet to which said riser is connected, a vapour outlet from said separator connected to a compressor, a liquid outlet from said separator connected to a pump, and valve means for selectively controlling flow of fluid from said liquid outlet, said valve means in the riser and in the liquid outlet being closed when the valve means in the branch is open, to withdraw only vapor from said container.

2. Apparatus for pumping a boiling liquid from a container and also for pumping gas from said container When required, which comprises a riser extending from a point near the bottom of the container, a branch on said riser communicating with the vapour space at the top of the container, valve means in said riser and in said branch to control flow of fluids from either the bottom of the riser or the said vapour space, a separator, to the inlet of which said riser is connected, a vapour outlet from said separator connected to a compressor, a liquid outlet from said separator connected to a pump, valve means for controlling flow of fluid from said liquid outlet, and additionally a heat exchanger downstream of the pump on the liquid outlet from the separator, a line communicating the compressor exit with said heat exchanger and a further separator in said line downstream of the heat exchanger.

3. Apparatus as claimed in claim 2 which includes a liquid discharge line from said further separato fitted with valve means and communicating said further separator with [the container.

3 4 4. Apparatus for selectively pumping a boiling liquid tively controlling fiow of fluid from said liquid outfrom a container in which it is stored at substantially let, atmospheric pressure and also for pumping gas from said (k) said first and third valve means being closed when container when required, comprising said second valve means is open to selectively de- (a) a riser extending from a point near the bottom 5 liver only vapor from said container,

of the container, (1) said second valve means being closed and said first (b) a branch on said riser communicating with a vapor and third valve means being open to deliver liquid space at the top of the container, from said container. (c) first valve means in said riser ahead of said branch, References Cited in the file of this patent (:1) second valve means in said branch, 10 (e) a separator having an inlet to which said riser is UNITED STATES PATENTS connected beyond said branch, Re. 18,646 Heylandt .d Nov. 1, 1932 (f) a vapor outlet from said separator, 1,505,095 Heylandt Aug. 19, 1924 (g) a compressor connected to said vapor outlet, 2,365,423 MacSporran Dec. 19, 1944 (h) a liquid outlet from said separator, 15 2,757,516 Buttolph Aug. 7, 1956 (i) a liquid pump connected to said liquid outlet, 2,871,668 Reed Feb. 3, 1959 (j) third valve means in said liquid outlet for selec- 2,895,305 Reed July 21, 1959 

1. APPARATUS FOR SELECTIVELY PUMPING A BOILING LIQUID FROM A CONTAINER IN WHICH IT IS STORED AT SUBSTNATIALLY ATMOSPHERIC PRESSURE AND ALSO FOR PUMPING GAS FROM SAID CONTAINER WHEN REQUIRED, WHICH COMPRISES A RISER EXTENDING FROM A POINT NEAR THE BOTTOM OF THE CONTAINER A BRANCH ON SAID RISER COMMUNICATING WITH THE VAPOUR SPACE AT THE TOP OF THE CONTAINER, VALVE MEANS IN SAID RISER AND IN SAID BRANCH TO SELECTIVELY CONTROL FLOW OF FLUIDS FROM EITHER THE BOTTOM OF THE RISER OR THE SAID VAPOUR SPACE, A SEPARATOR, HAVING AN INLET TO WHICH SAID RISER IS CONNECTED, A VAPOUR OUTLET FROM SAID SEPARATOR CONNECTED TO A COMPRESSOR, A LIQUID OUTLET FROM SAID SEPARATOR CONNECTED TO A PUMP, AND VALVE MEANS FOR SELECTIVELY CONTROLLING FLOW OF FLUID FROM SAID LIQUID OUTLET, SAID VALVE MEANS IN THE RISER AND IN THE LIQUID OUT- 